SWCODEC recording: Boost CPU frequency before doing flush on stop

If CPU is not boosted for some reason already, then the stop flush
can take longer than it really ought to.

Change-Id: I0572cc83067749e9945b3eb825f976db21d914f9

apps/recorder/pcm_record.c

@@ -1623,6 +1623,8 @@ static void on_record_stop(void)
     if (record_state == REC_STATE_IDLE)
         return;
 
+    trigger_cpu_boost();
+
     /* Drain encoder and PCM buffers */
     pcm_pause = true;
     finish_stream(true);